The retinal question

Retinal converts to retinoic acid in fewer steps than retinol, which means visible results faster and, counterintuitively, often less irritation at an equivalent strength.

The challenge is stability. Retinal degrades quickly when exposed to light and air, which is why most formulations either under-dose it or package it poorly.

The Renewal Serum uses an encapsulated, stabilized form in opaque, airless packaging — the kind of decision that costs more and shows up nowhere except in how the product performs six months in.